Photocatalytic hydrosilylation of conjugated dienes with triethylsilane in the presence Cr(CO)(6)

Abdelqader, W
Chmielewski, D
Grevels, FW
Özkar, Saim
Peynircioglu, NB
Chromium carbonyl photocatalyzed hydrosilylation of 1,3-butadiene, trans-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-butadiene, trans-2-methyl-1,3-pentadiene, and 1,3-cyclohexadiene with triethylsilane yields the cis-1,4-adducts, 1-(triethylsilyl)-2-butene derivatives, as the main products which have been isolated by distillation or preparative GC and fully characterized by NMR spectroscopy. The proposed mechanism involves the initial conversion of Cr(CO)(6) into Cr(CO)(4)(eta(4)-1,3-diene) followed by a further photolytic CO substitution by triethylsilane forming a Cr(CO)(3)(H)(SiEt(3))(eta(4)-1,3-diene) intermediate. Experiments with D-SiEt(3) lead to the conclusion that reversible addition of the hydride to the diene with formation of an eta(3)-enyl intermediate occurs prior to the irreversible silyl transfer to the organic moiety. The 1,4-hydrosilylation adduct is then replaced by new substrates to complete the catalytic cycle.


Chromium Bis(anthracene-(6)) Complexes - A DFT Study
Türker, Burhan Lemi (2018-04-03)
Chromium bisanthracene-(6) complexes are considered within the framework of density functional theory using LANL2DZ and 6-31+G(d) basis sets and B3LYP functional. The complexation with both the same types of rings of anthracene decks (AA- and BB-type complexes) and with different rings (AB-type complex) are considered. The optimized geometries and the associated quantum chemical properties are comparatively discussed for the both types of basis sets used. LANL2DZ basis set yielded some unreasonable results....
Photo-induced chromiumcarbonyl catalyzed hydrosilylation of conjugated dienes with triethylsilane: The solvent effect
Kayran, C; Özkar, Saim; Akhmedov, VM (2003-07-01)
Photocatalytic hydrosilylation of conjugated dienes (1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, trans-1,3-pentadiene) with triethylsilane was studied by using Cr(CO)(5)L (L = CO, P(CH3)(3), P(OCH3)(3), P(C6H5)(3), P(C6H11)(3), NC5H5) in two very different solvents, toluene and tetrahydrofuran, for comparison with the results found in n-hexane. In toluene, the photocatalytic hydrosilylation yields the same products as those in n-hexane, with the exception of trans-1,3-pentadiene which...
Photocatalytic hydrosilylation of conjugated dienes with triethylsilane in the presence of Cr(CO)(5)L(L=CO, P(CH3)(3), P(OCH3)(3))
Özkar, Saim; Kayran, C (Elsevier BV, 1997-04-15)
The effect of donor ligands on the chromium carbonyl photocatalysed hydrosilylation of 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, trans-1,3-pentadiene with triethylsilane was studied. Photocatalytic hydrosilylation of dienes conducted in the presence of Cr(CO)(5)L (L = P(CH3)(3) or P(OCH3)(3)) yields the cis-1,4-adducts, 1-triethylsilyl-2-butene derivatives, as the main products; these have been isolated by distillation or preparative GC and fully characterised by NMR spectroscopy. A...
Highly efficient and selective olefination of acyl phosphonates with ethyl diazoacetate catalyzed by a cobalt(II) porphyrin complex
Erturk, Erkan; Demir, Ayhan Sıtkı (Elsevier BV, 2008-08-04)
The cobalt(II) porphyrin complex (CoTPP) was found to be an efficient catalyst for the Wittig type olefination of acyl phosphonates with ethyl diazoacetate (EDA) in the presence of triphenylphosphine (Ph(3)P). By using this one pot methodology under mild conditions, densely functionalized vinyl phosphonates were obtained in high yields and high E/Z selectivities in relatively short reaction times. A rather broad substrate spectrum and steric influence on the reaction rate were observed.
Chemoenzymatic synthesis of enantiomerically enriched 2-oxobicyclo[m.1.0]alkan-3-yl acetate derivatives
ÖZDEMİRHAN, FAZİLET DEVRİM; ÇELİK, MURAT; ATLI, SELİN; Tanyeli, Cihangir (Elsevier BV, 2006-01-23)
Racemic alpha'-acetoxy alpha,beta-unsaturated cyclopentanone and cyclohexanone have been resolved into the corresponding enantiomerically enriched alpha'-hydroxylated and acetoxylated compounds with 96-97% ee via PLE hydrolysis. Stereoselectivity in the palladium(II)-catalyzed reaction between the enantiomerically enriched alpha'-acetoxylated compounds and diazomethane has been investigated. In the alpha'-acetoxylated cyclopentenone, preferential cyclopropanation occurs in the anti-form, whereas alpha'-acet...
Citation Formats
W. Abdelqader, D. Chmielewski, F. Grevels, S. Özkar, and N. Peynircioglu, “Photocatalytic hydrosilylation of conjugated dienes with triethylsilane in the presence Cr(CO)(6),” ORGANOMETALLICS, pp. 604–614, 1996, Accessed: 00, 2020. [Online]. Available: